fix: Fix missing Write trait and unused imports

src/digest_engine.rs

@@ -1,7 +1,5 @@
+use std::io::Write;
 use anyhow::{anyhow, Result};
-use std::io;
-
-use log::*;
 
 use lazy_static::lazy_static;
 
@@ -36,11 +34,23 @@ pub trait DigestEngine {
     fn update(&mut self, data: &[u8]);
 }
 
+use std::io::Write;
+
 // Writer that implements Write for the program digest engine
 struct ProgramWriter {
     stdin: std::process::ChildStdin,
 }
 
+impl Write for ProgramWriter {
+    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+        self.stdin.write(buf)
+    }
+
+    fn flush(&mut self) -> std::io::Result<()> {
+        self.stdin.flush()
+    }
+}
+
 lazy_static! {
     pub static ref DIGEST_PROGRAMS: EnumMap<DigestType, Option<DigestEngineProgram>> = enum_map! {
         DigestType::Sha256 => None,